Process of unhairing animal hides or skins.



No. 642.08I. Patented lan' 30, 1900. G. D. BURTON.

PROCESS 0F UNHAIRING ANIMAL HIDES 0R SKINS.

(Application led Mar. 5, 189B.)

' (No Model.) 2 Sheats-Sheet l,

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un. 64mm. y Patented 1an. 3u, mno.

. G. n. BURTON.'

PROCESS 0F UNHAIRING ANIMAL HIDES 0R SKINS.

(Application filed Mar. I5, 1898.)

(No Modal.) 2 Sheets-Sheet 2,

WIT 55555 Y Vl TMBM, I5 "#0 N ENTER UNTTT STATES PATENT OFFICE.

GEORGE D. BURTON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE UNITED STAT1S ELECTRICAL LEATHER PROCESS COMPANY, OE MAINE.

PROCESS OF UNHAIRING ANIMAL HIDES OR SKINS.

SPECIFICATTON forming part of Letters Patent No. 642,081, dated January30, 1900. Application iiled March 5, 1898. Serial No. 672,796. (Nospeoin1ens.)

To all whom t may con/067%:

Be it known that l, GEORGE D. BURTON, a citizen of the United States ofAmerica, residing' at Boston, in the county of Suffolk, in

the State of Massachusetts, have invented certain new and usefulImprovements in Processes of Unhairing Animal Hides or Skins, of whichthe following is a specification.

This invention consists in subjecting the io hides or skins to beunhaired to the action of a suitable unhairing solution and a current ofelectricity, which is passed through the solution in which the hides orskins are placed. It is believed that the electricity has a tendency toraise the hair somewhat from the hides or skins and prevent its becomingmatted thereon, and consequently the unhairing liquid has a freercirculation around the pores or hair-cells and softens the substancewhich holds the hair in such pores or cells more rapidly than in theordinary unhairing operation.

Figure l of the accompanying drawings is a view of an apparatus forcarrying out this process, comprising an electric generator, aswitch-table, and a tank for containing the unhairing solution throughwhich the electricity is passed, the generator and table being shown inside elevation and the tank in longitudinal vertical section. Fig. 2represents a plan view of the apparatus. Fig. 3 represents a verticaltransverse sect-ion of the tank on line at cc of Fig. 2.

The same reference-letters indicate corresponding parts in all thegures.

In carrying out this process the hides or skins to be unhaired areplaced in any suitable unhairing solution, and an electric current ispassed through said solution containing the hides or skins. Thecurrentof electricity may vary from one to twenty volts and from thirtyto seventy-five amperes, more or less, according to the volume andspecific gravity of the solution and the number of the hides or skinsplaced therein. A solution which I have found very effective for thispurpose consists of quicklime, red sultid of arsenic, and Water. I haveused these ingredients in the proportions of seventy gallons of water toten pounds of qnicklime and 5o one pound of red sulfid of arsenic. Aftermixing these ingredients the bath is stirred briskly for a few minutesuntil the lime becomes slaked and the arsenic dissolved. The solutionthen has suiiicient density to cause the necessary action to take place.Vhen the solution is formed With the ingredients specified in theproportions stated, the solution Will have a specic gravity of about1.025 at Fahrenheit. The bath 6o will of course assume the temperatureof the surrounding atmosphere in Which it is used. The hides or skins,which have been previously broken or softened by soaking in water or ina proper solution, are then placed in the bath or solution and allowedto remain there until the hair-cells become sufficiently softened toallow the hair to slip. I have found that a period of from one hour toone hour and a half, more or less, is required 7o forkangaroo, calf,orgoat skins. For oX and other hides a longer period may be required.The skins are then removed from the bath or solution, and the hair iseasily brushed or scraped off in the ordinary manner. Then the skins aresubjected to a thorough Washing, preferably in cold water, and they maythen be subjected immediately to the tanning process atter beingfleshed.

Under the ordinary process for removing 8o the hair the hides orskinshave to remain-in the solution for from fourteen to twenty days,and this process leaves the skins after they are unhaired in a conditionwhereby they have to be soaked in a prepared solution for some time inorder to bring them to a proper state to be treated by the tanningprocess.

I have also used a solution composed of seventy gallons of water, tenpounds of quicklime, one pound of red suliid of arsenic, and 9o onepound of alum. The addition of the alum causes the hair pores or cellsto rapidly contract as soon as the hair has been removed from the skin.By this process a heating of the solution beyond the temperature of thehide or skin when on the animal may be avoided, whereas in the ordinaryprocess the large quantity of quicklime used is liable to yIO heat thesolution beyond the point stated, and such heating tends to cause thehide or skin to pucker and shrink, and thus reduces the size of thefinished skin.

The apparatus herein shown for carrying out the process comprises a tankA, containing the unhairing solution B. This tank is preferably composedof or lined with Wood or other'non-conducting substance. Two electrodesD D are disposed in the tank, preferably at opposite ends thereof. Theseelectrodes are composed of any suitable material, preferably a materialwhich will not dissolve in or be acted upon by the solution. To this endthese electrodes are composed of a carbon composition of considerabledensity. These electrodes are connected by conductors H H with a switchF for controlling the electric current. This switch is connected byconductors J J with the dynamo D or other generator or source ofelectricity.

Screens C C, of Wood or other non-conducting material, are disposed inthe tank to prevent the hides or skins from coming in contact with theelectrodes D D. A screen E, also of Wood or other non-conductingmaterial, is supported in .the tank near the bottom thereof and servesto prevent the hides or skins from coming in direct contact with anylime which may settle in the bottom of the tank should the solutionremain too long unstirred. This screen is composed of a nonconductingsubstance and is preferably perforated, as shown in Fig. 3, so as topermit the lime to pass therethrough.

In carrying out the process by the use of this apparatus one of theunhairing solutions herein described or any suitable unhairing solutionis disposed in the tank A, and the hides or skins to be unhaired areplaced therein above the screen E and between the screens C C. Theelectric current is then turned on,.and the hides or skins are subjectedto the combined action of the solution and the current passingtherethrough until such hides or skins are in condition to permit thefree removal ofthe hair. The proportions of the ingredients used in thebath described may vary according tothe size of the tank and the numberof hides or skins to be treated at one time and the quantity of liquidused, and the electric current may be varied to meet the requirements ofthe hides to be treated.

It is believed that either of the unhairing solutions specified has atendency to preserve the hides or skins and in some degree to tan or putthe hides or skins in condition to facilitate the tanning action.

The arrangement of the electrodes at opposite ends of the tank enablesthe electric current to pass through the solution in lines parallel withthe layers of skins, and consequently the surfaces of the skins areexposed t0 the action of the current Without necessitating its passagethrough the bodies thereof I claim as my inventionl. The process ofunhairing animal hides or skins, which consists in subjecting the hidesor skins to the action of an unhairing solution and a current ofelectricity passed through said solution, said current entering saidsolution and passing out therefrom at points away from the hides orskins, and being of sufficient volume to raise the hair and permitcirculation through it.

2. The process of unhairing animal hides or skins, which consists insubjecting said hides or skins to the action of a solution of quicklime,and red sulid of arsenic, and an electric current passed through saidsolution, said current being of sufficient volume to raise the hair andpermit circulation through it.

3. The process of unhairing hides or skins, which consists in subjectingsaid hides or skins to the action of a solution composed of quicklime,red su-lid of arsenic, and Water in the proportions of about ten poundsof quicklime, one pound of red sulfid of arsenic, and seventy gallons ofWater, and an electric current passed through said solution containingthe hides or skins, said current being of sufficient volume to raise thehair and permit circulation through it.

4. The process of unhairing animal hides or skins, which consists insubjecting said hides or skins to the action of an unhairing solutionand a suitable electric current passed through said solution, andavoiding injury to said hides or skins by preventing their coming intodirect contact With sediment should the solution remain too longuns'tirred, said current being of sufficient volume to raise the hairand permit circulation through it.

.5. The process of unhairing animal hides or skins which consists insubjecting the hides or skins to the action of an unhairing solution anda current of electricity passed through said solution in lines parallelWith the layers of hides or skins,said current entering the solution andpassing out therefrom at points away from the hides or skins and beingof sufficient volume to raisethe hair and permit circulation through it.

In testimony that I claim the invention above set forth I affix mysignature in presence of two witnesses.

GEO. D. BURTON.

Witnesses:

O. P. ADAMS, GEO. STEINER.

IOO

ITO

